[R] Predicted value at a new level in lm

[Li Zhang]

    Y       X     Z 
   42.0    7.0   33.0
   33.0    4.0   41.0
   75.0   16.0    7.0
   28.0    3.0   49.0
   91.0   21.0    5.0
   55.0    8.0   31.0


data<-read.table("d.txt",header=TRUE)
mod<-lm(data$Y~data$X+data$Z)
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I would like to know the predict value at a new level,
say 

X=10 Z=30

Is there a function available to calculate it
directly?

Thank you